Extreme Optimization: Native Win32 Migration and Footprint Reduction

[0xarchit]

The current application architecture relies on several high-level dependencies (reqwest, tokio, dirs, winreg) that contribute significantly to binary bloat and idle memory overhead. Additionally, the event-driven system uses a polling-based message loop which introduces perceptible latency in UI interactions (Settings opening/closing) and resource transitions.

This issue tracks the migration to a "Pure Native" architecture to achieve a sub-600KB binary and instantaneous responsiveness.

Optimization Goals

1. Storage & Dependency Pruning

• Remove reqwest and tokio (approx. 800KB saving).
• Remove dirs and winreg crates.
• Replace lazy_static with standard library OnceLock.
• Implement a custom, minimalist file logger to replace env_logger.
• Migrate to native WinHTTP for updates and asset syncing.
• Migrate to SHGetKnownFolderPath for directory discovery.
• Migrate to native Reg* APIs for registry management.

2. Memory (RAM) Efficiency

• Downsampled Capture: Capture screen at 25% resolution to reduce transition buffers from ~66MB to ~4MB (16x saving).
• Static Buffer Reuse: Implement reusable static buffers for the capture and blur engines to eliminate heap churn.
• Idle Flushing: Explicitly shrink and clear heavy buffers to zero capacity when the application is idling in the tray.
• Resource Streaming: Use SHCreateStreamOnFileEx to stream media assets to WebView2 instead of loading full files into memory.

3. Responsiveness & Reliability

• Instant Wakeup: Implement PostThreadMessageW to wake the main message loop immediately when events occur, removing the 100ms-1s latency.
• Networking Hardening: Add strict timeouts and larger redirect buffers to the WinHTTP stack to prevent "stuck" update checks.
• Zero-Warning Build: Refactor code to meet strict compiler standards.

Technical Impact (Measured)

Metric	Before	After	Change
Binary Size	~2,048 KB	528 KB	-74%
Idle RAM	~4.5 MB	~3.5 MB	-22%
UI Latency	100ms - 1s	< 1ms	Instant

Notes

These changes ensure that PauseCat remains a professional-grade workstation utility that provides high-end visual effects (Gaussian blur, Glassmorphism) with the footprint of a legacy system tool.